package com.ld.businesscard_manage.DAO;

import com.ld.businesscard_manage.utils.JDBCUtilsByDruid;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;

public class BasicDAO<T>{
	private QueryRunner qr =  new QueryRunner();

	//开发通用的dml方法, 针对任意的表
	public int update(String sql, Object... parameters) {

		Connection connection = null;

		try {
			connection = JDBCUtilsByDruid.getConnection();
			int update = qr.update(connection, sql, parameters);
			return  update;
		} catch (SQLException e) {
			throw  new RuntimeException(e); //将编译异常->运行异常 ,抛出
		} finally {
			JDBCUtilsByDruid.close(null, null, connection);
		}

	}

	//返回多个对象(即查询的结果是多行), 针对任意表

	/**
	 *
	 * @param sql sql 语句，可以有 ?
	 * @param clazz 传入一个类的Class对象 比如 Actor.class
	 * @param parameters 传入 ? 的具体的值，可以是多个
	 * @return 根据Actor.class 返回对应的 ArrayList 集合
	 */
	public List<T> queryMulti(String sql, Class<T> clazz, Object... parameters) {

		Connection connection = null;
		try {
			connection = JDBCUtilsByDruid.getConnection();
			return qr.query(connection, sql, new BeanListHandler<T>(clazz), parameters);

		} catch (SQLException e) {
			throw  new RuntimeException(e); //将编译异常->运行异常 ,抛出
		} finally {
			JDBCUtilsByDruid.close(null, null, connection);
		}

	}

	//查询单行结果 的通用方法
	public T querySingle(String sql, Class<T> clazz, Object... parameters) {

		Connection connection = null;
		try {
			connection = JDBCUtilsByDruid.getConnection();
			return  qr.query(connection, sql, new BeanHandler<T>(clazz), parameters);

		} catch (SQLException e) {
			throw  new RuntimeException(e); //将编译异常->运行异常 ,抛出
		} finally {
			JDBCUtilsByDruid.close(null, null, connection);
		}
	}

	//查询单行单列的方法,即返回单值的方法

	public Object queryScalar(String sql, Object... parameters) {

		Connection connection = null;
		try {
			connection = JDBCUtilsByDruid.getConnection();
			return  qr.query(connection, sql, new ScalarHandler(), parameters);

		} catch (SQLException e) {
			throw  new RuntimeException(e); //将编译异常->运行异常 ,抛出
		} finally {
			JDBCUtilsByDruid.close(null, null, connection);
		}
	}
}
